Photoalignment composition

ABSTRACT

The present invention relates to a photoalignment composition comprising
     a) 0.001 to 20%, by weight, preferably, 1 to 10% by weight, more preferably 1 to 9% by weight of at least one photoreactive compound (I) that comprises a photoalignment group and   b) 80 to 99.999% by weight, preferably, 90 to 99% by weight, more preferably 91 to 99% by weight of at least one compound (II) that does not comprise a photoalignment group, and   c) optionally at least one reactive or non reactive additives, and   d) optionally at least one solvent.   

     Further the present invention relates to the use of this photoalignment composition for the alignment of liquid crystals or liquid crystal polymers, in electro-optical and optical elements, systems and devices.

The present invention relates to a photoalignment composition especiallyfor the alignment of liquid crystals or liquid crystal polymerscomprising

a) 0.001 to 20%, by weight, preferably, 0.05 to 10% by weight, morepreferably 0.1 to 9% by, especially more preferred 0.1 to 5%, moreespecially more preferred 0.1 to 2% weight of at least one photoreactivecompound (I) that comprises a photoalignment group andb) 80 to 99.999% by weight, preferably, 90 to 99% by weight, morepreferably 91 to 99% by weight of at least one compound (II) that doesnot comprise a photoalignment group, andc) optionally at least one reactive or non reactive additives, andd) optionally at least one solvent.

Further the present invention relates to the use of this photoalignmentcomposition for the alignment of liquid crystals or liquid crystalpolymers, in electro-optical and optical elements, systems and devices.

Liquid crystal devices are more and more used in many differentapplications. Examples are optical films, in particular polarizing filmsand retardation films, as well as security devices for preventingforgery, counterfeiting and copying and liquid crystal displays (LCD).

Liquid crystal displays (LCDs) are becoming increasingly dominant inadvanced visualization devices. LCDs offer favourable characteristicswith respect to image quality (high luminance, high resolution, colourand grey scale capability), power consumption as well as dimensions andweight (flat panel displays). The use of commercial LCDs has becomewidespread, e.g. in automotive and telecommunication instruments, aswell as in monitors of notebooks, desktop computers, television sets,etc. Today the need for LCDs in television applications is rapidlygrowing. Recently developed LCD modes possess high potentials inachieving fast response times, wide viewing angles and high luminance.Amongst other newly developed LCD modes, the MVA (multi-domain verticalalignment) mode appears to be the most promising for the use in moderntelevision applications. In the MVA mode the liquid crystal moleculesare usually nearly vertically aligned with respect to the surface of thesubstrates. By using protrusions (or other alignment subdivisions) onthe surface of the substrate, the liquid crystal molecules becomelocally pre-tilted within a single cell in more than one direction,leading to domains switchable in different directions. This multi-domainconfiguration exhibits very good display performance, with wide viewingangles of up to 160° in any direction, short response times (below 20ms), high contrast ratios (up to 700:1) and high brightness. However, bymeans of using protrusions only, it is difficult to clearly define thedomain space within a single pixel. Therefore the MVA mode demandsadditional manufacturing steps to ensure shape effects as well aselectrical field effects on both the upper and lower substrate; henceall in all leading to complex manufacturing procedures. In order toby-pass this technical challenge, the availability of an alignment layerwould be desirable, which directly leads to pre-defined alignmentdirections within each pixel domain and having well controllableoff-axis angles with respect to the normal axis of the substrate.

The successful functioning and performance of a liquid crystal device oroptical film relies on the ability of the liquid crystal moleculeswithin that device or film to adopt an alignment imposed upon them.Alignment of the liquid crystal molecules is achieved by use of analignment layer which defines a direction of orientation for the liquidcrystal molecules with the result that the longitudinal axes of themolecules become aligned with the direction of orientation defined bythe alignment layer. In addition to this directional alignment, for someapplications, the alignment layer should also be able to impart to theliquid crystal molecules an angle of tilt so that the molecules alignthemselves at an angle out of the surface of the alignment layer.

A well known method for preparing alignment layers is a rubbingtreatment wherein a high molecular resin film such as polyimide isrubbed in a single direction with a cloth. The liquid crystal moleculesadjacent to the rubbed surface are aligned in the rubbing direction.However, alignment films formed by rubbing have some disadvantages likedust generation and scratches, which occur during the rubbing process.In addition, rubbing methods are not adequate for the production ofstructured layers, i.e. layers having small areas with differentalignment directions.

These problems can be solved using liquid-crystal alignment controlprocesses other than rubbing such as oblique deposition,photolithographic, Langmuir Blodgett film, ion irradiation, highvelocity fluid jet and other processes. However, most of these processesare not practical for processing large-area substrates.

Other methods developed for the alignment of liquid crystals arealignment layers made by photo-orientation methods (usually usinglinearly polarized light), and especially well suited are linearlyphoto-polymerized (LPP) alignment layers, also known as photo-orientedpolymer networks (PPN). Such methods are for instance disclosed in U.S.Pat. No. 5,389,698, U.S. Pat. No. 5,838,407, U.S. Pat. No. 5,602,661,U.S. Pat. No. 6,160,597, U.S. Pat. No. 6,369,869, U.S. Pat. No.6,717,644, U.S. Pat. No. 6,215,539, U.S. Pat. No. 6,300,991, and U.S.Pat. No. 6,608,661. These methods allow the generation of homogeneousalignment of liquid crystals. In the LPP process, which is a non-contacttechnique, alignment films similar to those obtained by rubbing can beobtained with high reproducibility by irradiating a photosensitive filmon a large substrate area with polarized light. In addition, it ispossible to vary the direction of orientation and the azimuthal andpolar tilt angle within the photoreactive layer by controlling thedirection of the irradiation of the linearly polarized light. Byselectively irradiating specific regions of the photoreactive material,it is possible to align very specific regions of the layer and thus toprovide alignment areas having different orientation which gives rise tostructured alignment layer as described for example in Jpn. J. Appl.Phys., 31 (1992), 2155-64 (Schadt et al.). Using the linearlyphoto-polymerizable alignment (LPP) technique, the possibility ofrealizing a four-domain vertical aligned nematic (VAN) LCD wasdemonstrated some years ago (K. Schmitt, M. Schadt; Proceedings ofEuroDisplay 99, 6-9 Sep. 1999). The four-domain VAN-LCD exhibits anexcellent off-state angular brightness performance.

It is thus an object of the present invention to provide furtherphotoalignment materials.

Thus, the present invention relates to a photoalignment compositioncomprising

a) 0.001 to 20%, by weight, preferably, 1 to 10% by weight, morepreferably 1 to 9% by weight of at least one photoreactive compound (I)that comprises a photoalignment group andb) 80 to 99.999% by weight, preferably, 90 to 99% by weight, morepreferably 91 to 99% by weight of at least one compound (II) that doesnot comprise a photoalignment group, andc) optionally at least one reactive or non reactive additives, andd) optionally at least one solvent.

In the context of the present invention compound (II) are preferablymonomer(s), oligomer(s), dendrimer(s), polymers, copolymers orprepolymer(s), more preferred are polymers or copolymers.

Preferably compound (II) is poly-acrylate, -methacrylate, -imide, -amicacid, -amide, -ethylene, -ethyleneoxid, -propylene, -vinyl chloride,-ethylene terephthalate, -styrene, -carbonate, -acetic acid, -urethan,-ester, -ether, -silicon, more preferred is poly-acrylate,-methacrylate, -imide, -amic acid, -amide, -acetals, -(amide-imide)s,-acrylates, -(ether etherketone)s, -(ether-imide)s, -(phenylene oxide)s,-(phenylene sulfide)s, -sulfones; especially polyamic acid and/orpolyimide.

More preferred compound (II) is

-   Poly(3,3′,4,4′-benzophenonetetracarboxylic    dianhydride-co-4,4′-oxydianiline/1,3-phenylenediamine), amic acid-   Poly(3,3′,4,4′-benzophenonetetracarboxylic    dianhydride-co-4,4′-oxydianiline/1,3-phenylenediamine), amic acid-   Poly(pyromellitic dianhydride-co-4,4′-oxydianiline), amic acid-   Poly(3,3′,4,4′-benzophenonetetracarboxylic    dianhydride-co-4,4′-oxydianiline/1,3-phenylenediamine), amic acid-   Poly(3,3′,4,4′-benzophenonetetracarboxylic    dianhydride-co-4,4′-oxydianiline/1,3-phenylenediamine), amic acid-   Poly(pyromellitic dianhydride-co-4,4′-oxydianiline), amic acid;    or-   polyimide, polyamide or polyamic acid of the below given diamines    and dianhydrides, such as-   aromatic diamines:    such as for example diamino diphenyl derivatives, such as    4,4′-diaminodiphenyl ether, 4,4-diamino-2,2′-dichlorodiphenyl    disulfide, 4,4′-diaminodiphenyl sulfone,    4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylamine sulfate,    3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane,    3,3′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfide,    3,4′-diaminodiphenyl ether, 3,3′-dinitro-4,4′-diaminodiphenyl    sulfone, 3,3′,4,4′-tetraminodiphenylsulfone, 3,3-diamino diphenyl    urea, 4,4-diamino diphenyl urea, 4,4-diamino diphenyl-2-sulphonic    acid,    4,4′-diamino-diphenylene-cycylohexane,    4,4′-diaminodiphenylamine-2,2-disulphonic acid,    4,4′-diamino-5,5′-dimethyl-2,2′-biphenyl disulfonic acid disodium    salt,    4,4′-diamino-3,3′-dinitrodiphenyl ether,    4,4′-diamino-3,3′-dimethyldiphenyl methane,    3,3′-diamino-4,4′-dichlorodiphenyl sulfone;    or    diaminofluorene, such as 2,7-diaminofluorene,    9,9-bis(4-aminophenyl)fluorine, 3,7-diamino-2-methoxyfluorene,    2,7-diaminofluorene dihydrochloride;    or    diaminoanthraquinone, such as 1,5-diaminoanthraquinone,    1,8-diamino-4,5-dihydroxyanthraquinone, 2,6-diaminoanthraquinone,    1,5-diamino-4,8-dihydroxyanthraquinone,    4,5′-diamino-(1,1′)bianthracenyl-9,10,9′,10′-tetraone;    or    diaminobiphenyl, such as 4,4′-diaminooctafluorobiphenyl,    3,4′-diaminobiphenyl, 2,2′-biphenyldiamine,    4,4′-diamino-5,5′-dimethyl-2,2′-biphenyldisulfonic acid,    3,3′-diamino-4,4′-dihydroxybiphenyl,    4,4′-bis(4-aminophenoxy)biphenyl,    4,4′-diamino-2,2′-biphenyldisulfonic acid,    2,3′,4,5′,6-pentaphenyl-3,4′-biphenyldiamine;    or    benzidine derivatives such as 3,3′,5,5′-tetramethylbenzidine;    benzidines mixture, benzidine 3,3′-dichlorobenzidine    dihydrochloride, benzidine dihydrochloride, 3,3′-dihydroxybenzidine,    3,3′-dinitrobenzidine, benzidine sulfate, 3,3′-dichlorobenzidine,    3,3′-diaminobenzidine tetrahydrochloride, 3,3′-dimethoxybenzidine,    3,3′,5,5′-tetramethylbenzidine dihydrochloride, 2-nitrobenzidine,    3-methylbenzidine dihydrochloride, 3,3′-dimethylbenzidine    dihydrochloride, benzidine-3-sulfonic acid,    2,2′,5,5′-tetrachlorobenzidine,    2,2′-dichloro-5,5′-dimethoxybenzidine, 3-methoxybenzidine,    3,3′,5,5′-tetramethylbenzidine dihydrochloride hydrate,    3,3′-diaminobenzidine tetrahydrochloride dihydrate,    2,2′-dimethylbenzidine hydrochloride,    2,2′-bis(trifluoromethyl)benzidine, tetramethylbenzidine;    or    diamino bibenzyl derivatives such as    4,4′-diamino-2,2′-dimethylbibenzyl,    2,2′-diamino-4,4′-difluorobibenzyl,    3,5,3′,5′-tetrabromo-biphenyl-4,4′-diamine;    or    aniline derivative such as    4-[4-(4-aminophenoxy)-2,3,5,6-tetrafluorophenoxy]aniline,    4-[1-(4-aminophenyl)-1-methylethyl]aniline,    2-((5-[(2-aminophenyl)thio]-3,4-dinitro-2-thienyl)thio)aniline,    2,2′-dithiodianiline,    4,4′-(1,3-phenylenediisopropylidene)bisaniline,    2-[2-(2-aminophenyl)diaz-1-enyl]aniline,    2,2′-(phenylmethylenebis)bis(4-methylaniline),    4,4′-methylene-bis(2-chloroaniline), 2,2′-oxydianiline,    2-((6-[(2-aminophenyl)sulfanyl]-5-nitro-2-pyridyl)sulfanyl)aniline,tetrabromo    methylenedianiline, 4,4′-azodianiline,    4-[3-(4-aminophenoxy)propoxy]aniline, 2,2′-ethylenedianiline    diphosphate, chrysaniline, 4,4′-dithiodianiline,    4,4′-ethylenedianiline, pararosaniline acetate,    3,3′-(decamethylenedioxy)dianiline,    3-nitro-4,4′-methylenedianiline,3,3′(pentamethylenedioxy)dianiline,    4-(p-aminoanilino)-3-sulfoaniline,    4,4′-methylenebis(3-chloro-2,6-diethylaniline),    4,4′-methylene-bis-(2,6-diethylaniline),    4,4′-methylenebis-(2,6-diisopropylaniline),    2,2′-(hexamethylenedioxy)dianiline,    2,2′-(pentamethylenedioxy)dianiline, 2,2′-(ethylenedioxy)dianiline,    4-[4-(4-aminophenoxy)butoxy]aniline,    2-([2-[(2-aminophenyl)thio]-6-nitro-4-(trifluoromethyl)phenyl]thio)aniline,    2-[(3-([(2-aminophenyl)thio]methyl)-2,4,6-trimethylbenzyl)thio]aniline,    3-[3-amino-5-(trifluoromethyl)benzyl]-5-(trifluoromethyl)aniline,    2-((5-[(2-aminophenyl)thio]-4-chloro-2-nitrophenyl)thio)aniline,    4-(1-(4-aminophenyl)-2-[4-(dimethylamino)phenyl]vinyl)aniline;    or    diamino acridine derivative such as 3,6-acridinediamine,    3,6-diaminoacridine hemisulfate hemihydrate, 3,6-diaminoacridine    hydrochloride, 3,6-diamino-10-methylacridinium chloride,    3,6-diamino-10-methylacridinium chloride hydrochloride;    or diamino stilbene derivative such as 4,4′-diaminostilbene    dihydrochloride, 4,4′-diaminostilbene-2,2′-disulfonic acid;    or diamino benzophenone derivative such as 3,3′-diaminobenzophenone;    or-   pararosaniline hydrochloride-   2,2′-dithiobis(1-naphthylamine)-   propidium iodide-   o-dianisidine dihydrochloride-   proflavine dihydrochloride-   o-tolidine dihydrochloride-   proflavine hemisulfate    or-   o-tolidine-   2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane-   4,4′-diamino-1,1′-dianthramide-   3-amino-4-hydroxyphenyl sulfone-   4,4-bis-(3-amino-4-hydroxyphenyl)-valeric acid-   2-amino-4-chlorophenyl disulfide-   4,4′-diaminobenzanilide-   n,n′-bis(3-aminophenylsulfonyl)ethylenediamine-   proflavine hemisulphate-   phenosafranin-   4,4′-diaminobenzophenone-   2,2-bis(4-aminophenyl)hexafluoropropane-   2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane-   2,2-bis(3-amino-4-methylphenyl)hexafluoropropane-   2,2-bis[4-(4-aminophenoxy)phenyl]propane-   1,4-bis(4-aminophenoxy)benzene-   1,3-bis(4-aminophenoxy)benzene-   bis[4-(4-aminophenoxy)phenyl]sulfone-   o-tolidine sulfone-   3,6-thioxanthenediamine-10,10-dioxide-   2,5-bis-(4-aminophenyl)-(1,3,4)oxadiazole-   3,3′-dimethylnaphthidine-   1,3-bis(3-aminophenoxy)benzene-   4,4′-diamino-1,1′-binaphthyl-   diamine bordeaux-   benzoflavin-   2,2′-thiobis(5-aminobenzenesulfonic acid)-   benzidine pyrophosphate-   3,6-diaminothioxanthene-10-dioxide, dihcl-   4,4″-diamino-p-terphenyl-   bis(p-aminophenoxy)dimethylsilane-   bis[4-(3-aminophenoxy)phenyl]sulfone-   4,4′-methylenedi-2,6-xylidine-   2-aminobenzaldehyde-ethylene-diamine-   toluylenediamine-   3,8-diamino-6-phenylphenanthridine-   thionin perchlorate-   dihydroethidium-   thionin-   4,4-diamino benzene sulfonyl anilide-   o-dianisidine hcl-   2,2′-diamino-4′-methoxy-4-methylbenzanilide-   5,5′-dimethyl-2,2′-dinitrobenzidine-   n,n′-bis(2-aminophenyl)-1,3-propanediamine-   3,4′-diaminochalcone-   2-([1-(4-(1-[(2-aminophenyl)thio]-2-nitroethyl)phenyl)-2-nitroethyl]thio)aniline-   2-((2-[(2-aminophenyl)thio]ethyl)thio)aniline-   2-((4-[(2-aminophenyl)thio]but-2-enyl)thio)aniline-   2,2′-diamino-bibenzyl-   trimethylene bis(4-aminobenzoate)-   fluoresceinamine-   1,6-diaminopyrene-   1,8-diaminopyrene-   3,6-diaminocarbazole-   4,4′(5′)-diamino-[2,4]-dibenzo-18-crown-6,dihydrochloride-   4,4′-diaminostilbene-2,2′-disulfonic acid, disodium salt-   (r)-(+)-2,2′-diamino-1,1′-binaphthyl-   proflavine hemisulfate dihydrate-   dimidium bromide monohydrate-   o-tolidine dihydrochloride hydrate-   3,6-[bis(4-amino-3-(sodiumsulphonato)phenylamino)]-2,5-dichloro    4-benzoquinone-   2,7-diamino-9-fluorenone-   n,n′-bis(2-aminophenyl)oxamide-   n,n′-bis(4-aminophenyl)-1,3-bis(aminomethyl)benzene dihydrochloride-   4′,4″(5″)-diaminodibenzo-15-crown-5-   bis(4-amino-2,3-dichlorophenyl)methane-   alpha,alpha′-bis(4-aminophenyl)-1,4-diisopropylbenzene-   2,2-bis(3-aminophenyl)hexafluoropropane-   3,10-diamino-6,13-dichlorobenzo[5,6][1,4]oxazino[2,3-b]phenoxazine-4,11-disulfo-   n1-(2-amino-4-methylphenyl)-2-aminobenzamide-   n1-(2-amino-4-chlorophenyl)-2-aminobenzamide-   2,2′-dichloro[1,1′-biphenyl]-4,4′-diamine-   4,4′(5′)-diaminodibenzo-15-crown-5 dihydrochloride-   rcl s19, 413-1-   bis-(4-amino-3-nitro-phenyl)-methanone-   bis-(3-amino-4-chloro-phenyl)-methanone-   bis-(3-amino-4-dimethylamino-phenyl)-methanone-   n,n′-bis-(4-amino-2-chloro-phenyl)-isophthalamide-   n,n′-bis-(4-amino-2-chloro-phenyl)-terephthalamide-   3,9-diamino-1,11-dimethyl-5,7-dihydro-dibenzo(a,c)cyclohepten-6-one-   2-aminobenzaldehyde n-[(z)-(2-aminophenyl)methylidene]hydrazone-   3,3′-bis(trifluoromethyl)benzidine-   dicarboxidine 2 hcl-   1,4-phenylenebis[[4-(4-aminophenoxy)phenyl]methanone]-   n′1-(2-aminobenzoyl)-2-aminobenzene-1-carbohydrazide-   2-[4-(5-amino-1 h-benzimidazol-2-yl)phenyl]-1 h-benzimidazol-5-amine-   bis(4-aminophenyl)acetylene-   dibenzo(1,2)dithiine-3,8-diamine-   ethidium homodimer-2-   4,4′-bis-(2-aminobenzenesulfonyl)bis-phenolester-   neopentyl glycol bis(4-aminophenyl)ether-   3,3′-tolidine-5-sulfonic acid-   n1-(3-[(2-aminobenzoyl)amino]propyl)-2-aminobenzamide-   2-((6-amino-1,3-benzothiazol-2-yl)dithio)-1,3-benzothiazol-6-ylamine-   2-([6-[(2-aminophenyl)sulfanyl]-3,5-di(trifluoromethyl)-2-pyridyl]sulfanyl)    anil-   3,6-diaminothioxanthene-10-dioxide dihydrochloride-   m-tolidine dihydrochloride hydrate-   2-amino-n-[2-amino-4-(trifluoromethyl)phenyl]-5-methylbenzamide-   1,5-bis(4-aminophenoxy)pentane-   2,3′-dichlorobenzidine dihydrochloride-   3-(bis-(4-amino-phenyl)methyl)-2,3-dihydro-isoindol-1-one    alicyclic diamines:-   4,4′-methylenebis(cyclohexylamine)-   4,4′-methylenebis(2-methylcyclohexylamine)    aliphatic diamines:-   1,8-diamino-p-menthane-   4,4′-methylenebis(cyclohexylamine)-   d-cystine-   I-cystine dimethyl ester dihydrochloride-   neamine-   bis(2-aminopropyl)amine-   (h-cys-beta-na)2 2 hcl-   I-cystine dibenzyl ester ditosylate-   1,4-diaminocyclohexane-   (h-cys-pna)2-   dl-2-aminopropionic anhydride-   I-cystine(di-b-naphthylamide)hydrochloride-   I-cystine-bis-p-nitroanilide dihydrobromide-   I-cystine diethyl ester dihydrochloride-   trans-1,4-cyclohexanediamine-   4,4′-methylenebis(2-methylcyclohexylamine)-   I-leucinethiol, oxidized dihydrochloride-   1,3-diaminoadamantane dihydrochloride-   I-leucinethiol disulfide 2 hcl-   I-cystine disodium salt, monohydrate-   I-homocystine methylester hydrochloride-   1,3-adamantanediamine-   tetracyclo[8.2.1.1(8,11)0.0(2,7)]tetradeca-2,4,6-triene-10,11-diamine    tricyclo[3.3.1.0(3,7)]nonane-3,7-diamine.

The polyimides and polyamic acids of the invention preferably comprisedianhydride selected from the group given below:

-   tetrahydro-2,5-dioxa-cyclobutadicyclopentene-1,3,4,6-tetraone-   pyromellitic dianhydride-   3,3′,4,4′-benzophenonetetracarboxylic dianhydride-   1,4,5,8-naphthalenetetracarboxylic dianhydride-   3,4,9,10-perylenetetracarboxylic dianhydride-   tetrahydrofuran-2,3,4,5-tetracarboxylic dianhydride-   4-(2,5-dioxotetrahydrofuran-3-yl)-tetralin-1,2-dicarboxylic    anhydride-   cis,cis,cis,cis-1,2,3,4-cyclopentanetetracarboxylic dianhydride-   3,3′,4,4′-biphenyltetracarboxylic dianhydride-   5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic    anhydride-   4,4′-(hexafluoroisopropylidene)diphthalic anhydride-   4,4′-oxydiphthalic anhydride-   3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride-   bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride-   1,2,3,4-cyclopentanetetracarboxylic dianhydride-   ethylene maleic anhydride-   1,14-dimethyl-4,10-dioxatetracyclo[5.5.2.0(2,6)0.0(8,12)]tetradec-13-ene-3,5,9,1    ethylenediaminetetraacetic dianhydride-   bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride-   ethylene glycol bis(trimellitic anhydride)-   tricyclo[4.2.2.0(2,5))dec-9-ene-3,4,7,8-tetracarboxylic dianhydride-   4,4′-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride)-   4,5,9,10-tetrabromo-isochromeno(6,5,4-def)isochromene-1,3,6,8-tetraone-   (5,1′,1′,5″)terisobenzofuran-1,3,3′,1″,3″-pentaone-   meso-butane-1,2,3,4-tetracarboxylic dianhydride-   bicyclo[2.2.2]-oct-7-ene-2,3:5,6-tetra-carboxylic dianhydride-   3,7-dimethyl-11,16-dioxapentacyclo[6.5.5.0(1,6)0.0(9,13)0.0(14,18)]octadec-6-ene-1-   3,9-dioxa-spiro(5.5)undecane-2,4,8,10-tetraone-   1,4-ethano-8-me-144a566a78-octa-h-bz(c)phenanthren-5613,14-tetr-co2h    dianhydride; and    copolymers of more than two of the foregoing polymers.

Further preferred is compound (I), which is a polyimide selected fromthe group consisting of poly(pyromellitic dianhydride-4,4′-oxydiamine),poly(pyromelliticdianhydride-2,2-bis([-(4-aminophenoxy)phenyl]-hexafluoropropane),poly(pyromellitic dianhydride-2,2-bis(4-aminophenoxyphenyl) propane),poly(1,2,3,4-cyclobutanetetracarboxylic acid-4,4′-oxydiamine),poly(1,2,3,4-cyclobutanetetracarboxylicacid-2,2-bis-[4-(4-aminophenoxy)phenyl]-hexafluoropropane),poly(1,2,3,4-cyclobutanetetracarboxylicacid-2,2-bis(4-aminophenoxyphenyl)-propane),poly(2,2-bis(3,4-dicarboxyphenyl)hexafluoropropanedianhydride-4,4′-oxydiamine), poly(2,2-bis(3,4-dicarboxyphenyl)hexafluoropropanedianhydride-2,2-bis[4-(4-aminophenoxy)phenyl]-hexafluoropropane),poly(2,2-bis(3,4-dicarboxyphenyl)hexafluoropropanedianhydride-2,2-bis(4-aminophenoxyphenyl)propane), poly(pyromelliticdianhydride-2,2-bis[4-(4-aminophenoxy)phenyl]-hexafluoropropane)-4,4′-oxydiamine),Poly(3,3′,4,4′-benzophenonetetracarboxylicdianhydride-co-4,4′-oxydianiline/1,3-phenylenediamine), amic acid;Poly(3,3′,4,4′-benzophenonetetracarboxylicdianhydride-co-4,4′-oxydianiline/1,3-phenylenediamine), amic acid;Poly(pyromellitic dianhydride-co-4,4′-oxydianiline), amic acid:Poly(3,3′,4,4′-benzophenonetetracarboxylicdianhydride-co-4,4′-oxydianiline/1,3-phenylenediamine), amic acid;Poly(3,3′,4,4′-benzophenonetetracarboxylicdianhydride-co-4,4′-oxydianiline/1,3-phenylenediamine), amic acid;Poly(pyromellitic dianhydride-co-4,4′-oxydianiline), amic acid, andcopolymer of more than two of the monomers used for the preparation ofsaid polymers.

In the context of the present invention “photoalignment groups” areanisotropically absorbing groups useful in the preparation of alignmentlayers.

In a preferred embodiment of the present invention the photoalignmentgroups induce anisotropic molecular alignment of liquid crystals byirradiation with aligning light. Preferred photoalignment groupsdimerize and/or to undergo trans-cis isomerisation or which are able tophoto-degradate, preferably they are able to undergo trans-cisisomerisation and/or dimerize and more preferably they are able todimerize.

In the context of the present invention the wording “photo-degradate” isattributed to the anisotropic depolymerization of a polymer, preferablypolyimide.

These photoreactions are for example described in J. Phys. D: Appl.Phys., 33, R67-R84 (2000).

Preferred photoreactive compounds (I) are monomer(s), oligomer(s),dendrimer(s), polymers, copolymers or prepolymer(s), more preferred arepolymers or copolymers.

In the context of the present invention:

the terms “polymer” and “copolymer”, refer to a monomer with a highermolecular weight, typically higher than 5000 g/mol;

the terms “oligomer” and “prepolymer” refer to a monomer with a highermolecular weight,

typically lower than 5000 g/mol;the term “dendrimer” refers to a molecule comprising perfectly branchedrepeat units in layers emanating radially from a point-like core.

In the context of the invention polymer denotes homo- or hetero-polymer,copolymer or prepolymer.

Preferably the photoreactive compounds (I) are polymers, preferablypoly-acrylate, -methacrylate, -imide, -amic acid, -amide, -ethylene,-ethyleneoxid, -propylene, -vinyl chloride, -ethylene terephthalate,-styrene, -carbonate, -acetic acid, -urethan, -ester, -ether, -silicon,more preferred is poly-acrylate, -methacrylate, -imide, -amic acid,-amide, -acetals, -(amide-imide)s, -acrylates, -(ether etherketone)s,-(ether-imide)s, -(phenylene oxide)s, -(phenylene sulfide)s, -sulfonesand mixtures thereof;

And more preferably the polymers of (I) are polyamic acid and/orpolyamic acid.

Further more preferred are photoreactive compound (I) comprisingphotoalignment groups, which are radicals of alpha,beta-unsaturated-carbonyl groups, preferably ciannamates, coumarine,quinolone, cyanostilbene, chalcone, diphenylacetylene,benzylidenephtalimidine, benzylideneacetophenone, phenylenediacryloyl,stilbazole, azo, polyimides and their derivatives; especially cinnamate;coumarin, anthraquinone, mericyanine, methane, 2-phenylazothiazole,2-phenylazobenzthiazole, quinolone, diarylketones, such as benzophenonesuch as 4,4′-diaminobenzophenone, 4,4′-bis(trifluoromethyl)benzophenone,3,4′-bis/trifluoromethyl)benzophenone,3,3′-bis(trifluoromethyl)benzophenone; benzophenone imine; thephenylhydrazones of benzophenone, 4′-bis(trifluoromethyl)benzophenone,3,4′-bis/trifluoromethyl)benzophenone or3,3′-bis(trifluoromethyl)benzophenone; 2,4-diaminiophenylhydrazones ofbenzophenone, 4′-bis(trifluoromethyl)benzophenone,3,4′-bis/trifluoromethyl)benzophenone or3,3′-bis(trifluoromethyl)benzophenone; phenylhydrazones, semicarbazones;benzylidenephtalimidine, benzylideneacetophenone, phenylenediacryloyl,diphenylacetylene, stilbene, 1,4-bis(2-phenylethylenyl)benzene,4,4′-bis(arylazo)stilbenes, perylene, 4,8-diamnion-1,5-naphthoquinone,cyanostilbene, diphenylacetylene, chalcone, stilbazole, organic azos,such as arylazo, di(arylazo), tri(arylazo), tetra(arylazo),penta(arylazo), reversible azo-containing polymers.

Further most preferred are photoreactive compound (I) comprisingphotoalignment groups, which are radicals of alpha,beta-unsaturated-carbonyl groups, preferably cinnamates, coumarine,quinolone, cyanostilbene or chalcone,

In the context of the invention, the term liquid crystal denotes liquidcrystal or liquid crystal polymer or liquid crystal pre-polymer.

Liquid crystal polymer or liquid crystal pre-polymer are for exampleLC242, (manufactured by BASF Corp., with a trade name of LC246), orthose disclosed in WO00/48985, WO00/55110, WO99/37735, WO00/39631 (Mon1,Mon2, Mon3 on page 5), WO99/64924, WO99/37735, WO05/054406, WO00/04110,WO00/05189, WO03/027056, WO98/52905, U.S. Pat. No. 5,800,733, U.S. Pat.No. 5,851,424, U.S. Pat. No. 5,851,427, U.S. Pat. No. 5,593,617, U.S.Pat. No. 5,567,349, which are herewith incorporated by reference.

More preferred photoreactive compounds (I) comprise photoalignmentgroups, which are substituted or unsubstituted and preferably alpha,beta-unsaturated-carbonyl groups, especially those photoalignment groupsof formula II; III and IV respectively

whereinthe broken line indicates the linkage in the photoreactive compoundrespectively;C represents an aromatic group which is unsubstituted or substituted byfluorine, chlorine or cyano, or by a cyclic, straight-chain or branchedalkyl residue which is unsubstituted, mono-substituted by cyano orhalogeno, or poly-substituted by halogeno, having 1 to 18 carbon atomsand wherein one or more non adjacent CH₂ groups may independently bereplaced by Q, wherein Q represents—O—, —CO, —CO—O—, —O—CO—, —NR¹—, —NR¹—CO—, —CO—NR¹—, —NR¹—CO—O—,—O—CO—NR¹—, —NR¹—CO—NR¹—, —CH═CH—, —C≡C—, —O—CO—O—, and—Si(CH₃)₂—O—Si(CH₃)₂—, an aromatic and an alicyclic group;E represents —OR⁴, —NR⁵R⁶, or an oxygen atom linked to ring C in theortho-position to form a coumarin unit, wherein R⁴, R⁵ and R⁶ are ahydrogen atom or a cyclic, straight-chain or branched alkyl residuewhich is unsubstituted, mono-substituted by halogeno, orpoly-substituted by halogeno, having 1 to 18 carbon atoms and whereinone or more CH₂ groups may independently be replaced by —O—, —CO—,—CO—O—, —O—CO—, —CH═CH—, with the proviso that oxygen atoms are notdirectly attached to each other, or R⁵ and R⁶ are linked together toform an alicyclic ring with 5 to 8 atoms; andX, Y each independently of the other represents hydrogen, fluorine,chlorine, cyano, alkyl optionally substituted by fluorine having from 1to 12 carbon atoms in which optionally one or more non-adjacent CH₂groups are replaced by —O—, —CO—O—, —O—CO— and/or —CH═CH—;andmore especially preferred are cinnamate groups and its derivatives,especially those of formulae:

and more especially those of formulae:

whereby the aromatic rings are unsubstituted or substituted andwherein the compound residue (Ia)

represents a straight-chain or branched C₁-C₁₆-fluoralkyl group, wherein

-   F is fluorine, and-   x is an integer from 0 to 15, preferably an integer from 0 to 10;    more preferably 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9 and most preferred 0    or 3, 4, 5 or 7;-   B represents a straight-chain or branched C₁-C₁₆alkyl group, which    is in addition to its fluorine substituent(s) unsubstituted or    substituted by    -   di-(C₁-C₁₆alkyl)amino, C₁-C₆alkoxy, nitro, cyano and/or        chlorine; and wherein one or more —CH₂— group may independently        from each other be replaced by a linking group;-   S₁ and S₂ independently from each other denote a spacer unit.

The term “spacer unit” as used in the context of the present invention,is preferably a single bond, a cyclic, straight-chain or branched,substituted or unsubstituted C₁-C₂₄alkylen, wherein one or more,preferably non-adjacent, —CH₂— groups may independently from each otherbe replaced by a linking group,

wherein linking group, as used in the context of the present inventionis preferably be selected from —O—, —CO, —CO—O—, —O—CO—,

—NR¹—, —NR¹—CO—, —CO—NR¹—, —NR¹—CO—O—, —O—CO—NR¹—, —NR¹—CO—NR¹—,—CH═CH—, —C≡C—, —O—CO—O—, and —Si(CH₃)₂—O—Si(CH₃)₂—, and wherein:R¹ represents a hydrogen atom or C₁-C₆alkyl;and/or a non-aromatic, aromatic, unsubstituted or substitutedcarbocyclic or heterocyclic group connected via bridging groups (II),and is more preferably the linking group is selected from —O—, —CO—,—CO—O—, —O—CO—;wherein.bridging group (II) as used in the context of the present invention ispreferably selected from —CH(OH)—, —CO—, —CH₂(O)—, —SO—, —CH₂(SO)—,—SO₂—, —CH₂(SO₂)—, —COO—, —OCO—, —COCF₂—, —CF₂CO, —S—CO—, —CO—S—, —SOO—,—OSO—, —SOS—, —O—CO—O—, —CH₂—CH₂—, —OCH₂—, —CH₂O—, —CH═CH—, —C≡C—,—CH═CH—COO—, —OCO—CH═CH—, —CH═N—, —C(CH₃)═N—, —N═N— or a single bond; ora cyclic, straight-chain or branched, substituted or unsubstitutedC₁-C₂₄alkylen, wherein one or more —CH₂— groups may independently fromeach other be replaced by a linking group as described above,with the proviso that oxygen atoms of linking groups are not directlylinked to each other.

More preferably S₁ and S₂ are independently from each other —CO—O—,—O—CO— or —O—, and most preferably S₁ is —O— and S₂ is —CO—O— or —O—CO—.

Preferably B is a straight-chain or branched C₁-C₁₂alkyl, wherein one ormore, preferably non-adjacent, —CH₂— group(s) may independently fromeach other be replaced by a group selected from —O—, —CO, —CO—O—,—O—CO—, —NR¹—, —NR¹—CO—, —CO—NR¹—, —NR¹—CO—O—, —O—CO—NR¹—, —NR¹—CO—NR¹—,—CH═CH—, —C≡C—, —O—CO—O—, and —Si(CH₃)₂—O—Si(CH₃)₂—, an aromatic and analicyclic group; and wherein:

R¹ represents a hydrogen atom or C₁-C₆alkyl;with the proviso that oxygen atoms are not directly linked to eachother.

More preferably, B is a straight-chain or branched C₁-C₁₂alkyl, whereinone or more, preferably non-adjacent, —CH₂— group(s) may be replaced bya group selected from from —O—, —CO, —CO—O—, —O—CO—, —NR¹—, —NR¹—CO—,—CO—NR¹— or —CH═CH— wherein:

R¹ represents a hydrogen atom or C₁-C₆alkyl;with the proviso that oxygen atoms are not directly linked to eachother.

Most preferably, B is a straight-chain or branched C₁-C₈alkyl, whereinone or more, preferably non-adjacent, —CH₂— group(s) may be replaced bya group selected from from —O—, —CO, —CO—O—, —O—CO—, —NR¹—, —NR¹—CO—,—CO—NR¹- or —CH═CH— wherein:

R¹ represents a hydrogen atom or C₁-C₆alkyl;with the proviso that oxygen atoms are not directly linked to eachother.

Especially most preferably, B is a straight-chain or branchedC₁-C₈alkyl, wherein one or more, preferably non-adjacent, the —CH₂—group may be replaced by a group selected from —O—, —CO—, —CO—O—,—O—CO—, and —CH═CH—, with the proviso that oxygen atoms are not directlylinked to each other.

And further more preferred photoreactive compound (I) comprisesphotoalignment groups, which are, radicals of coumarine, quinolone,cyanostilbene,

especially such as cyanostilbene of formulae:

whereby the aromatic rings are unsubstituted or substituted.

Preferred substituents of the photoalignment groups are substituted orunsubstituted C₁-C₂₄alkyl, preferably C₁-C₁₀ alkyl residue, morepreferably C₁-C₈ alkyl residue, which is unsubstituted, mono-substitutedby cyano or halogeno, or poly-substituted by halogeno, wherein one ormore non adjacent CH₂ groups may independently be replaced by a group Q,wherein Q represents —O—, —CO—, —CO—O—, —O—CO—, —Si(CH₃)₂—O—Si(CH₃)₂—,—NR²—, —NR²—CO—, —CO—NR²—, —NR²—CO—-O—, —O—CO—NR²—, —NR²—CO—NR²—,—CH═CH—, —C≡C—, —O—CO—O—, preferably Q represents —O—, —CO—, —CO—O—; andwherein R² represents hydrogen or C₁-C₆alkyl; with the proviso thatoxygen atoms of linking groups are not directly linked to each other.

In addition preferred photoreactive compounds (I) are herewithincorporated by reference:

-   -   alpha, beta-unsaturated-carbonyl, especially cinnamic acid        derivatives as described in U.S. Pat. No. 6,610,462,B1, U.S. Re        36,625, EP 0 763 552 B1(GB), U.S. Pat. No. 5,965,761, U.S. Pat.        No. 6,277,502 B1, U.S. Pat. No. 6,632,909 B2, U.S. Pat. No.        6,107,427, U.S. Pat. No. 5,539,074, WO 00/59966, WO99/15576        WO01/07495, WO 01/53384 A1, WO 2006/039824 A1, WO2007/071091,        WO2008/135131; WO2008/145225; Macromolecules, 14, 95 (1981)    -   coumarine and Quinolone derivatives as described in U.S. Pat.        No. 6,201,087 B1, J. SID, 5/4, 367 (1997), Nature, 351, 212        (1996)    -   cyanostilbene derivatives as described in WO07/033,506    -   Chalcone derivatives as described in J. Photopolym. Sci.        Technol., 11, 187 (1998)    -   Diphenylacetylene derivatives as described in Chem. Mat., 11,        1293 (1999)    -   Benzylidenephtalimidine derivatives as described in Macromol.        Chem. Phys., 199, 375 (1998)    -   Benzylideneacetophenone derivatives as described in Macromol.        Chem. Phys., 199, 363 (1998)    -   Phenylenediacryloyl derivatives as described in Japan. J. Appl.        Phys., 1, 37, 2620 (1998)    -   Stilbazole derivatives as described in J. Photopolym. Sci.        Technol., 12, 279 (1999)    -   Azo derivatives as described in Chemical Reviews, 100, 1847        (2000)    -   Polyimides, which photo-degradate by use of linear polarized UV        light as described in Appl. Phys. Lett., 72, 1832-1833 (1998).

In the context of the present invention the unreactive additives relatefor example to antioxidants, accelerators, dyes, inhibitors, activators,fillers, pigments, anti-static agents, flame-retardant agents;stabilizing additives, such as curing inhibitors, or retardants, such asfor example hydroquinone; p-tert.-butyl catechol; 2,6-ditert.-butyl-p-methylphenol; phenothiazine; N-phenyl-2-naphthylamine;thickeners, thixotropic agents, surface-active agents, viscositymodifiers, extending oils, plasticizers, tackifiers, catalysts,sensitizers, stabilizers, such as e.g. phenol derivatives, such as4-ethoxyphenol or 2,6-di-tert-butyl-4-methylphenol (BHT), lubricatingagents; dispersing agents, hydrophobing agents, adhesive agents, flowimprovers, initiator, especially thermal or photo initiator, defoamingagents, deaerators, diluents, curing inhibitors, auxiliaries, colorants,dyes, pigments or a photo-orientable monomer or oligomer or polymer asdescribed in EP 1 090 325 B. Promoters or accelerators such as metalsalts and amines may be used with the initiators.

Reactive additives denote a polymerizable reactive additive. Further,reactive additives are for example selected from the below listed groupof additives, which carry at least one polymerizable group: cross-linkersuch as described in EP 0 331 233, WO 95/24454, U.S. Pat. No. 5,567,349,U.S. Pat. No. 5,650,534, WO 00/04110, WO 00/07975, WO 00/48985, WO00/55110 and WO 00/63154, which are herewith incorporated; diluent,liquid crystal, accelerators, dyes, inhibitors, activators, fillers,chain transfer inhibitor, pigments, anti-static agents, flame-retardantagents, thickeners, thixotropic agents, surface-active agents, viscositymodifiers, extending oils, plasticizers, tackifiers, catalysts,sensitizers, stabilizers, lubricating agents; dispersing agents,hydrophobing agents, adhesive agents, flow improvers, defoaming agents,deaerators, diluents, auxiliaries, colorants, dyes and pigments.

The composition is solid, or diluted in a solvent, which is an organicsolvent and/or water, as a solution, gel, dispersion or emulsion.

Preferably, the composition is a clear solution. The solvent or solventmixture used in the present application may be any compound that candissolve the composition (VI) according to the invention. At least onesolvent such as a common polar solvent or a nonpolar solvent may beused. The solvents which are particularly preferred are those leading toa good coatability or printability of the solution of the material tothe substrate to be coated.

Non-polar solvents are compounds that have low dielectric constants andare not miscible with water, such as for example hexane, benzene,toluene, diethyl ether, chloroform, ethyl acetate, dichloromethane.Polar solvents are aprotic or protic. Polar aprotic solvents aresolvents that share ion dissolving power with protic solvents but lackacidic hydrogen. These solvents generally have high dielectric constantsand high polarity. Examples are 1,4-dioxane, tetrahydrofuran (THF),acetone, acetonitrile (MeCN), dimethylformamide (DMF), dimethylsulfoxide (DMSO), N-methylpyrrolidone (NMP), ethylpyrrolidone,N-vinylpyrrolidone, 2-butoxyethanol (BC), gamma.-butyrolactone (BL),N-methylmorpholine, gamma.-butyrolactone, acetonitrile, ethylcarbitol,butylcarbitol, ethylcarbitol acetate, ethylene glycol, propylene glycolmonoacetate, propylene glycol diacetate, dipropylene glycol, anddipropylene glycol monomethyl ether, chlorobenzene, tetrahydrofuran,butylcellosolve, cyclopentanone (CP), methylethylketone (MEK), ethylacetate (EA), anisole (AN), cyclohexanone (CHN), methyl isobutyl ketone(MIBK), 1-methoxy-2-propanol acetate (MPA), N,N-dimethyl-formamide(DMF), dichloromethane, gamma-butyrolactone (BL), and mixtures thereof.Polar protic solvents are solvents, which contain dissociable H+, suchas hydrogen fluoride. The molecules of such solvents can donate anH+(proton). Conversely, aprotic solvents cannot donate hydrogen bonds.Common characteristics of protic solvents are to display hydrogenbonding, to have an acidic hydrogen (although they may be very weakacids), to be able to stabilize ions (cations by unshared free electronpairs, anions by hydrogen bonding). Examples are acetic acid, n-butanol,isopropanol, n-propanol, ethanol, methanol, formic acid and water.

Preferably the organic solvents used in the present application areprotic or aprotic polar or non-polar solvents.

Preferred solvents are, however not limited to:

-   -   ketones such as for example acetone, cyclopentanone (CP),        cyclohexanone (CH), methyl isobutyl ketone (MIBK),        methylethylketone (MEK),    -   amides such as N,N-dimethylformamide (DMF), N-methylpyrrolidone        (NMP), M-ethylpyrrolidone, N-vinylpyrrolidone,        N,N-dimethylacetamide,    -   carbamates    -   ether such as anisole (AN), tetrahydrofuran (THF), ethylene        glycol, dipropylene glycol, butylcarbitol, ethylcarbitol        acetate, dipropylene glycol monomethyl ether,    -   ester such as ethyl acetate (EA), 1-methoxy-2-propanol acetate        (MPA), gamma-butyrolactone (BL), propylene glycol monoacetate,        propylene glycol diacetate, dipropylene glycol monomethyl ether,    -   alcohols, such as 2-butoxyethanol (BC), ethylcellosolve,        butylcellosolve,    -   dimethyl sulfoxide (DMSO),    -   halogen hydrocarbons such as dichloromethane, chlorobenzene,    -   apolar solvents as for example, however not limited to        hydrocarbons, such as hexane, heptane, toluene; petrolether.        and mixtures thereof.

More preferred solvents are acetone, cyclopentanone (CP), cyclohexanone(CH), methyl isobutyl ketone (MIBK), methylethylketone (MEK),N,N-dimethylformamide (DMF), N-methylpyrrolidone (NMP),N-ethylpyrrolidone, N-vinylpyrrolidone, N,N-dimethylacetamide, (AN),tetrahydrofuran (THF), ethylene glycol, dipropylene glycol,butylcarbitol, ethylcarbitol acetate, dipropylene glycol monomethylether, ethyl acetate (EA), 1-methoxy-2-propanol acetate (MPA),gamma-butyrolactone (BL), butylcellosolve (BC), dichloromethane,propylene glycol monoacetate, propylene glycol diacetate, dipropyleneglycol monomethyl ether, anisole (AN), N,N-dimethylformamide (DMF),dimethyl sulfoxide (DMSO) and mixtures thereof.

Most preferred are cyclopentanone (CP), cyclohexanone (CH), methylisobutyl ketone (MIBK), methylethylketone (MEK), ethyl acetate (EA),1-methoxy-2-propanol acetate (MPA), dimethyl sulfoxide (DMSO), anisole(AN), N,N-dimethylformamide (DMF), dichloromethane, gamma-butyrolactone(BL), N-methylpyrrolidone (NMP), butylcellosolve (BC) and mixturesthereof.

The amount of the reactive or non reactive additives in the compositionis determined according to the wished performances in respect oforientation capability of the photoalignment layer and of its mechanicaland thermal stability, as well as of its optical and electroopticalperformances. Preferably, the reactive or non reactive additives have anamount of 0.1 to 50% by weight of the composition, preferably an amountof 1 to 30% by weight, even more preferably an amount of 1 to 10% byweight.

In case the compositions of the invention comprise a stabilizer, thelatter is generally present in an amount of 0.01 to 5% by weight of thecomposition, preferably in an amount of 0.1 to 1% by weight.

The solvent is used to aid the coating of the composition. Typicalconcentrations of the composition disposed in a solvent are between 1and 50%, preferred between 1 and 10% by weight of the active ingredientsin said solvent(s).

In a preferred embodiment of the present invention the photoalignmentcomposition is phase separated having the at least one photoreactivecompound (I) in the upper part of the composition.

In a further embodiment the present invention concerns the use of acomposition according to the present invention for the preparation ofphotoalignment material, preferably for a photoalignment layer.

The present invention relates also to photoalignment materialscomprising a composition according to the present invention, andpreferably a phase-separated composition of the present invention.

The compounds of the invention may be readily prepared using methodsthat are well known to the person skilled in the art, such as thosedocumented in Houben-Weyl, Methoden der Organischen Chemie,Thieme-Verlag, Stuttgart.

The present invention also relates to a process for the preparation ofphotoalignment material, preferably photoalignment layer, comprising

a) applying a composition, wherein said composition has the same meaningand preferences as given above; and thenb) optionally drying, and thenc) irradiating the applied composition (VII), obtained after step a) orstep b), with aligning light to induce the anisotropy.

The applied composition (VII) is preferably a film.

In general, for the polymerization, the active ingredients are firstlyprepared separately from the individual components that are blended.

In general the material for the alignment layer is applied by generalcoating and printing methods known in the art. Non limiting examples ofmethods for the patterned deposition of the alignment layer include anycoating and printing process involve the application of a thin film ofthe functional material to a substrate, but are not limited to:spin-coating, blade coating, knife coating, kiss roll coating, castcoating, slot-orifice coating, calendar coating, electrodepositingcoating, die coating, dipping, brushing, casting with a bar,roller-coating, flow-coating, injection-molding, wire-coating,spray-coating, dip-coating, whirler-coating, cascade-coating,curtain-coating, air knife coating, gap coating, rotary screen, reverseroll coating, gravure coating, metering rod (Meyer bar) coating, slotdie (Extrusion) coating, hot melt coating, roller coating, flexocoating, silk screen coater, relief printing such as flexographicprinting, ink jet printing, intaglio printing such as direct gravureprinting or offset gravure printing, lithographic printing such asoffset printing, or stencil printing such as screen printing.

The substrate is in general glass or plastic, which is optionally coatedwith indium tin oxide (ITO).

The layer thickness of the composition on the substrate is preferablyhigher than 5 nm, more preferably between 10 and 800 nm, most preferablybetween 20 and 100 nm.

It depends on the consistence of the composition whether a drying stepis conducted. If solvents are comprised by the composition, thecomposition is usually dried after the applying step.

In general “drying” consists in the extraction of the solvent(s) forexample by application of heated gas using for example an air streamthat applies the heat by convection and carries away the vapor ofsolvents (convective or direct drying). Drying is faster at highertemperatures. Product or film qualities also have to be considered inthe determination of the temperature applied for the drying. Otherpossibilities are vacuum drying, where heat is supplied by contactconduction or radiation (or microwaves) while the produced vapor isremoved by the vacuum system; indirect or contact drying (heatingthrough a hot wall), as drum drying, vacuum drying; dielectric drying(radiofrequency or microwaves being absorbed inside the material);freeze drying or lyophilization; mechanical extraction of the solvent.

The term “aligning light” is light of wavelengths, which can induceanisotropy in the photoalignment layer. Preferably, the wavelengths arein the UV-A, UVB and/or UV/C-range, or in the visible range. It dependson the photoalignment compound, which wavelengths are appropriate.Preferably, the photo-reactive groups are sensitive to visible and/or UVlight. The UV light is preferably selected according to the absorptionof the photo-reactive groups, i.e. the absorption of the film shouldoverlap with the emission spectrum of the lamp used for the LP-UVirradiation, more preferably with linearly polarized UV light. Theintensity and the energy used are chosen depending on thephotosensitivity of the material and on the orientation performanceswhich are targeted. In most of the cases, very low energies (few mJ/cm2)already lead to high orientation quality.

More preferably, “aligning light” is at least partially linearlypolarized, elliptically polarized, such as for example circularlypolarized, or non-polarized, most preferably circularly polarized, ornon-polarized light exposed obliquely, or at least partially linearlypolarized light. Especially, most preferred aligning light denotessubstantially polarised light, especially linearly polarised light; oraligning light denotes non-polarised light, which is applied by anoblique irradiation.

More preferably, the aligning light is UV light, preferably linearlypolarized UV light.

Preferably, the present invention relates to a process for thepreparation of photoalignment material, preferably photoalignment layer,comprising

a) applying a composition, wherein said composition has the same meaningand preferences as given above; and thenb) optionally drying, and thenc) irradiating the applied composition (VII), obtained after step a) orstep b), with aligning light to induce the anisotropy, whereby thecomposition of step a) or the applied composition (VII) have avertically phase separated morphology, and whereby the photoreactivecompound (I) is preferably located at the film/liquid crystal interfaceor interphase.

More preferably the concentration of photoreactive compound (I) is 10times higher in the upper part than in the lower part.

Further more preferred is a process, wherein the composition of step a)comprises a photoreactive compound (I) and a compound (II) that phaseseparate.

Further more preferred is a process, wherein the photoalignment layerthickness is below 300 nm, most preferred below 150 nm.

The present invention also relates to a photoalignment material for theorientation of liquid crystals especially for LCDs or thin films.

In the context of the present invention the photoalignment material is alayer, preferably in form of a network.

The present invention also relates to a photoalignment material,preferably an unstructured or structured photoalignment material,obtainable by the processes as described above.

The term “structured” refers to a variation in the orientation of thephotoalignment material, which is induced by locally varying thedirection of the polarized aligning light.

The term “structured” refers to a two dimensional structured layer inthe plane, or a three dimensional structured layer in the space, wherebythe pattern is periodic or non-periodic. The methods of patterning asdescribed in WO2008/077261 and are herewith incorporated by reference.

Three dimensional forms are for example specific surface reliefstructures such as inclined or curved liquid crystal polymer structureslike e.g. micro-lens or micro-prism structures.

More preferred the wording “patterned layer” denotes birefringencepatterned layer and/or thickness patterned layer and/or patterned layerhaving a patterned optical axis orientation, and/or patterned degree ofpolymerization.

Accordingly the term “patterning” denotes the process step ofpreparation the patterned layer.

Birefringence denotes the difference between the extra-ordinary and theordinary index of refraction.

The local degree of polymerization is quantifiable by a measurement ofthe local ratio of the unreacted polymerizable groups in the liquidcrystal composition after the polymerization.

In addition, the present invention relates to the use of thephotoalignment material as a photalignment layer, for aligning organicor inorganic compounds, especially for aligning liquid crystals orliquid crystal polymers.

The present invention also relates to the use of the photoalignmentmaterial of the invention in the manufacture of optical orelectro-optical component and systems, especially multilayer systems, ordevices for the preparation of

a display waveguide, a security or brand protection element, for examplefor banknotes, credit cards, luxury articles, passports, and the like; abar code, an optical grating, a filter, a retarder, a compensation film,a reflectively polarizing film, an absorptive polarizing film, ananisotropically scattering film compensator and retardation film, atwisted retarder film, a cholesteric liquid crystal film, a liquidcrystal display, a guest-host liquid crystal film, a monomer corrugatedfilm, a smectic liquid crystal film, a polarizer, a piezoelectric cell,a thin film exhibiting non linear optical properties, a decorativeoptical element, a brightness enhancement film, a component forwavelength-band-selective compensation, a component for multi-domaincompensation, a component of multiview liquid crystal displays, anachromatic retarder, a polarization state correction/adjustment film, acomponent of optical or electro-optical sensors, a component ofbrightness enhancement film, a component for light-basedtelecommunication devices, a G/H-polarizer with an anisotropic absorber,a reflective circular polarizer, a reflective linear polarizer, a MC(monomer corrugated film), twisted nematic (TN) liquid crystal displays,hybrid aligned nematic (HAN) liquid crystal displays, electricallycontrolled birefringence (ECB) liquid crystal displays, supertwistednematic (STN) liquid crystal displays, optically compensatedbirefringence (OCB) liquid crystal displays, pi-cell liquid crystaldisplays, in-plane switching (IPS) liquid crystal displays, fringe fieldswitching (FFS) liquid crystal displays, vertically aligned (VA) liquidcrystal displays, multidomain vertically aligned (MVA) liquid crystaldisplays; all above display types are applied in either transmissive orreflective or transflective mode.

The optical or electro-optical component and systems, especiallymultilayer systems and devices can be patterned or unpatterned.

The term patterning preferably denotes to birefringence patterningand/or thickness patterning and/or patterning of the optical axisorientation, and/or patterning of the degree of polymerization.Birefringence denotes the difference between the extra-ordinary and theordinary index of refraction.

Thus the invention further relates to an optical or electro-opticalelements, systems and devices device comprising photoalignment material,within the above given meaning and preferences.

Preferred are optical or electro-optical elements, systems and devicescomprising photoalignment layer and at least one orientable layer, suchas a liquid crystal layer or liquid crystal polymer layer.

An optical component, system or device creates, manipulates, or measureselectromagnetic radiation.

An electro-optical component, system or device operates by modificationof the optical properties of a material by an electric field. Thus itconcerns the interaction between the electromagnetic (optical) and theelectrical (electronic) states of materials.

The photoalignment material has the ability to align compounds, such asfor example nematic liquid crystals, with their long axis along apreferred direction.

The present invention also relates to the use of the photoalignmentmaterial, preferably in cross-linked form, as a photalignment layer, foraligning organic or inorganic compounds, especially for aligning liquidcrystals.

The term “anisotropy” or “anisotropic” refers to the property of beingdirectionally dependent. Something which is anisotropic may appeardifferent or have different characteristics in different directions.

Preferred is the use for the induction of planar alignment, tilted orvertical alignment of adjacent liquid crystalline layers; more preferredis the use for the induction of planar alignment or vertical alignmentin adjacent liquid crystalline layers.

Most preferred is the use of the photoalignment material for adjusting atilt angle of liquid crystals.

The gist of the present invention lies in the utilization of the thiol,preferably polythiol of formula (V) for the networks. The inventors havefound that by the adjunction of monomers bearing thiol moieties,exceptionally high photosensitivities and alignment performances couldbe achieved. This fact vastly facilitates the manufacture of thenetworks and alignment layers sought using much reduced energy incomparison to former processes. Moreover, the orientation properties ofthe alignment layers are considerably improved in comparison withsimilar, known alignment layers prepared from low molecular weightphoto-crosslinkable materials as described in U.S. Pat. No. 6,610,462B1. Furthermore, very high concentrations of initiator (10-20 weight %of Irgacure 369) were required for the preparation of the photoalignedfilm which might lead to undesirable effects on the LC alignment qualityand/or on the LCD performances.

The inventors were able to synthesize a broad range of differentphoto-crosslinkable materials of different molecular weights havingvarious absorption properties which offer the possibility to better fitthe absorption characteristics of these materials to the emissionspectrum of the applied aligned light.

The characteristics of the resulting polymer or network can be targetedto desired performances by controlling the thermal and photo-curingprocess.

In addition, the blends of the invention give access to very goodvoltage holding ratios, which is important for LCD applications. Forlarge scale production, the blends comprising only low amounts of themore expensive photoalignment component the blends give access to moreeconomic photoaligning material.

EXAMPLES Definitions Used in the Examples

prepared as described in WO07/071,091 examples 9 and 18 (polyamic acid18 and polyimide 18)

Polymer 2 is prepared in analogy to methods known in the art such as forexample Polymerisation step: Formation of the polyamic acid

6 g (30.26 mmol) of 4,4′-diaminodiphenyl derivative(4,4′-diaminodiphenyl methane, 4,4′-diaminodiphenyl thioether,4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl glutaric ester) wassolubilised in 71 mL of 1-methyl-2-pyrrolidone (NMP). The mixture wascooled to 0° C. for 10 minutes. 6.648 g (29.66 mmol) of2,3,5-tricarboxycyclopentylacetic-1,2:3,4-dianhydride were added to thesolution. The mixture was stirred at 0° C. for two hours and then at rtfor 3 hours. The reaction gave the polyamic acid precursor having aviscosity of 0.4 dL/g.

prepared as described in WO07/071,091 examples 9 and 18 (polyamic acid18 and polyimide 18)

Prepared as described in analogy to U.S. Pat. No. 6,632,909

Prepared as described in analogy to WO96/10049

Prepared as described in analogy to U.S. Pat. No. 6,107,427

Liquid crystal polymer 1: Composition A in anisol (1:20)Composition A: the composition comprises,LCP1 (see below given structure),LCP 2 (see below given structure),Tinuvin 123 (manufactured by Ciba Specialty Chemicals),Irgacure 369 (manufactured by Ciba Speciality Chemicals),butyl-hydroxy-toluolhaving the following ratios (78.43:18.63:0.98:0.98:0.98)

Prepared as described in WO00/39631

Prepared as described in U.S. Pat. No. 6,676,851

Example 1

A liquid crystal cell was prepared wherein the liquid crystal wasaligned by photo reactive polymer 1.

A 4% solution of polymer 1 was prepared by mixing the solid polymer 1 inthe solvent n-methyl-2-pyrrolidone(NMP) and stirred thoroughly till thesolid polymer 1 is dissolved and a second solvent butyl cellulose(BC) isadded and the whole composition is stirred thoroughly to obtain finalsolution. The solvent ratio between n-methyl-2-pyrrolidone and butylcellulose is 1:1.

The above polymer solution was spin-coated onto the two ITO coated glasssubstrates at a spin speed of 1600 rpm for 30 seconds.

After spin coating the substrates were subjected to baking procedureconsisting of pre-baking for 5 minutes at 130° C. and post-baking for 40minutes at a temperature of 200° C. The resulting layer thickness wasaround 60 nm.

The substrates with the coated polymer layer on top were exposed tolinearly polarized UV light(LPUV) at an incidence angle of 40° relativeto the normal of the substrate surface. The plane of polarization waswithin the plane spanned by the substrate normal and the propagationdirection of the light. The applied exposure dose was 48 mJ/cm².

After LPUV exposure a cell was assembled with the 2 substrates, theexposed polymer layers facing to the inside of the cell. The substrateswere adjusted relative to each other such that the induced alignmentdirections were parallel to each other (corresponds to the anti-parallelrubbed configuration in case of alignment by rubbing procedure). Thecell was capillary filled with liquid crystal MLC6610(Merck KGA), whichhad a negative dielectric anisotropy.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 87.7° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 2

Another cell was prepared with the same processing and exposureconditions as in Example 1, except that the solution to be coatedcomprised of polymer 2 instead of polymer 1 and the spin speed used was2100 rpm for 30 seconds.

Between crossed polarizers the cell appeared bright, independent of theangle between the polarizers and the edges of the substrates of thecell.

Consequently, the liquid crystals were not aligned in vertical directionand there was no preferred azimuthal orientation direction. Because ofthe missing orientation, a tilt angle could not be determined. However,from the bright appearance of the cell it was concluded that the liquidcrystal molecules were oriented almost planar. This interpretation fitswith the fact that polymer 2 is a commercial material used as anorientation layer for liquid crystals in twisted nematic LCDs, wheretypically tilt angles of a few degrees are required.

Example 3

Polymer 1 and polymer 2 were mixed in ratio of 20:80 per weight % toform a blend composition. A 4% solution was prepared as per theprocedure explained in Example 1 except that the two polymers were mixedin the solvent at the same time.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 and polymer 2 in ratio of 20:80 per weight % and the spinspeed used was 1900 rpm for 30 seconds.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 87.7° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 4

Polymer 1 and polymer 2 were mixed in ratio of 10:90 per weight % toform a blend composition. A 4% solution was prepared as per theprocedure explained in Example 1 except that the two polymers were mixedin the solvent at the same time.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 and polymer 2 in ratio of 10:90 per weight % and the spinspeed used was 2000 rpm for 30 seconds.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 87.6° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 5

Polymer 1 and polymer 2 were mixed in ratio of 5:95 per weight % to forma blend composition. A 4% solution was prepared as per the procedureexplained in Example 1 except that the two polymers were mixed in thesolvent at the same time.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 and polymer 2 in ratio of 5:95 per weight % and the spin speedused was 2050 rpm for 30 seconds.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 87.9° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 6

Polymer 1 and polymer 2 were mixed in ratio of 4:96 per weight % to forma blend composition. A 4% solution was prepared as per the procedureexplained in Example 1 except that the two polymers were mixed in thesolvent at the same time.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 and polymer 2 in ratio of 4:96 per weight % and the spin speedused was 2000 rpm for 30 seconds.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 87.5° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 7

Polymer 1 and polymer 2 were mixed in ratio of 3:97 per weight % to forma blend composition. A 4% solution was prepared as per the procedureexplained in Example 1 except that the two polymers were mixed in thesolvent at the same time.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 and polymer 2 in ratio of 3:97 per weight % and the spin speedused was 2000 rpm for 30 seconds.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 87.7° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 8

Polymer 1 and polymer 2 were mixed in ratio of 2:98 per weight % to forma blend composition. A 4% solution was prepared as per the procedureexplained in Example 1 except that the two polymers were mixed in thesolvent at the same time.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 and polymer 2 in ratio of 2:98 per weight % and the spin speedused was 2000 rpm for 30 seconds.

A tilt angle of 0.04° was measured using the crystal rotation method.The cell was arranged between crossed polarizers without any voltageapplied, with the director of liquid crystal in the cell set at 45° tothe axis of crossed polarizers, and the cell has bright appearance whichconcludes that the liquid crystal molecules were oriented almost planar.The cell was again arranged between crossed polarizers without anyvoltage applied, with the director of liquid crystal in the cell set at0° to any one of the transmission axis of the polarizers, the cell hasdark appearance, which concludes the well defined azimuthal orientationdirection of liquid crystal lying in the polarization plane of the LPUVlight used for photo exposure.

Example 9

Polymer 1 and polymer 2 were mixed in ratio of 1:99 per weight % to forma blend composition. A 4% solution was prepared as per the procedureexplained in Example 1 except that the two polymers were mixed in thesolvent at the same time.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 and polymer 2 in ratio of 1:99 per weight % and the spin speedused was 2000 rpm for 30 seconds.

A tilt angle of 0.02° was measured using the crystal rotation method.The cell was arranged between crossed polarizers without any voltageapplied, with the director of liquid crystal in the cell set at 45° tothe axis of crossed polarizers, and the cell has bright appearance whichconcludes that the liquid crystal molecules were oriented almost planar.The cell was again arranged between crossed polarizers without anyvoltage applied, with the director of liquid crystal in the cell set at0° to any one of the transmission axis of the polarizers, the cell hasdark appearance, which concludes the well defined azimuthal orientationdirection of liquid crystal lying in the polarization plane of the LPUVlight used for photo exposure.

Example 10

Polymer 1 and polymer 2 were mixed in ratio of 0.5:99.5 per weight % toform a blend composition. A 4% solution was prepared as per theprocedure explained in Example 1 except that the two polymers were mixedin the solvent at the same time.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 and polymer 2 in ratio of 0.5:99.5 per weight % and the spinspeed used was 2000 rpm for 30 seconds.

A tilt angle of 0.02° was measured using the crystal rotation method.The cell was arranged between crossed polarizers without any voltageapplied, with the director of liquid crystal in the cell set at 45° tothe axis of crossed polarizers, and the cell has bright appearance whichconcludes that the liquid crystal molecules were oriented almost planar.The cell was again arranged between crossed polarizers without anyvoltage applied, with the director of liquid crystal in the cell set at0° to any one of the transmission axis of the polarizers, the cell hasdark appearance, which concludes the well defined azimuthal orientationdirection of liquid crystal lying in the polarization plane of the LPUVlight used for photo exposure.

Example 11

Polymer 1 and polymer 2 were mixed in ratio of 0.2:99.8 per weight % toform a blend composition. A 4% solution was prepared as per theprocedure explained in Example 1 except that the two polymers were mixedin the solvent at the same time.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 and polymer 2 in ratio of 0.2:99.8 per weight % and the spinspeed used was 2000 rpm for 30 seconds.

A tilt angle of 0.02° was measured using the crystal rotation method.The cell was arranged between crossed polarizers without any voltageapplied, with the director of liquid crystal in the cell set at 45° tothe axis of crossed polarizers, and the cell has bright appearance whichconcludes that the liquid crystal molecules were oriented almost planar.The cell was again arranged between crossed polarizers without anyvoltage applied, with the director of liquid crystal in the cell set at0° to any one of the transmission axis of the polarizers, the cell hasdark appearance, which concludes the well defined azimuthal orientationdirection of liquid crystal lying in the polarization plane of the LPUVlight used for photo exposure.

Example 12

Polymer 1 and polymer 2 were mixed in ratio of 0.1:99.9 per weight % toform a blend composition. A 4% solution was prepared as per theprocedure explained in Example 1 except that the two polymers were mixedin the solvent at the same time.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 and polymer 2 in ratio of 0.1:99.9 per weight % and the spinspeed used was 2000 rpm for 30 seconds.

A tilt angle of 0.02° was measured using the crystal rotation method.The cell was arranged between crossed polarizers without any voltageapplied, with the director of liquid crystal in the cell set at 45° tothe axis of crossed polarizers, and the cell has bright appearance whichconcludes that the liquid crystal molecules were oriented almost planar.The cell was again arranged between crossed polarizers without anyvoltage applied, with the director of liquid crystal in the cell set at0° to any one of the transmission axis of the polarizers, the cell hasdark appearance, which concludes the well defined azimuthal orientationdirection of liquid crystal lying in the polarization plane of the LPUVlight used for photo exposure.

Example 13

A cell was prepared with the same processing and exposure conditions asin Example 1, except that solution used comprises of polymer solution Awhich is a commercial material OPTMER AL60702(JSR corporation) used asan orientation layer for liquid crystals in vertically aligned LCDs,where high tilt angles are required, and also except that the spin speedused was 3000 rpm for 30 seconds

The liquid crystals were oriented in vertical direction. A tilt angle of90° was measured using the crystal rotation method. Upon applying avoltage of 5V to the electrodes of the cell, the liquid crystalmolecules switched from the vertical orientation to a planarorientation, which was observed by arranging the cell between crossedpolarizers, but there was no preferred azimuthal orientation direction.

This material was used in blend composition for further Examples 14, 15,16 and 17 by replacing the polymer 2 of blend compositions listed inExamples 7, 8, 9 and 10.

Example 14

A blend composition in ratio of 3:97 per weight % was prepared usingpolymer 1 listed in Example 1 and polymer solution A listed in Example13 as per the procedure explained in Example 1 except that the solventsused were n-methyl-2-pyrrolidone, butyl cellulose and gammabutyrolactone in ratio of 3:3:4.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 listed in Example 1 and polymer solution A listed in Example13 in ratio of 3:97 per weight % and the spin speed used was 2700 rpmfor 30 seconds.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 88.0° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 15

A blend composition in ratio of 2:98 per weight % was prepared usingpolymer 1 listed in Example 1 and polymer solution A listed in Example13 as per the procedure explained in Example 1 except that the solventsused were n-methyl-2-pyrrolidone, butyl cellulose and gammabutyrolactone in ratio of 3:3:4.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 listed in Example 1 and polymer solution A listed in Example13 in ratio of 2:98 per weight % and the spin speed used was 2700 rpmfor 30 seconds.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 88.5° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 16

A blend composition in ratio of 1:99 per weight % was prepared usingpolymer 1 listed in Example 1 and polymer solution A listed in Example13 as per the procedure explained in Example 1 except that the solventsused were n-methyl-2-pyrrolidone, butyl cellulose and gammabutyrolactone in ratio of 3:3:4.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 listed in Example 1 and polymer solution A listed in Example13 in ratio of 1:99 per weight % and the spin speed used was 2700 rpmfor 30 seconds.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 89.4° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 17

A blend composition in ratio of 0.5:99.5 per weight % was prepared usingpolymer 1 listed in Example 1 and polymer solution A listed in Example13 as per the procedure explained in Example 1 except that the solventsused were n-methyl-2-pyrrolidone, butyl cellulose and gammabutyrolactone in ratio of 3:3:4.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 1 listed in Example 1 and polymer solution A listed in Example13 in ratio of 0.5:99.5 per weight % and the spin speed used was 2700rpm for 30 seconds.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 89.8° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 18

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the polymer 3 was used instead of polymer 1and the spin speed used was 2000 rpm for 30 seconds.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 88.7° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 19

An experiment was performed with similar combination as in Example 10,except that the polymer 1 is replaced by polymer 3 listed in Example 18.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 3 and polymer 2 in ratio of 0.5:99.5 per weight % and the spinspeed used was 2000 rpm for 30 seconds.

A tilt angle of 0.02° was measured using the crystal rotation method.The cell was arranged between crossed polarizers without any voltageapplied, with the director of liquid crystal in the cell set at 45° tothe axis of crossed polarizers, and the cell has bright appearance whichconcludes that the liquid crystal molecules were oriented almost planar.The cell was again arranged between crossed polarizers without anyvoltage applied, with the director of liquid crystal in the cell set at0° to any one of the transmission axis of the polarizers, the cell hasdark appearance, which concludes the well defined azimuthal orientationdirection of liquid crystal lying in the polarization plane of the LPUVlight used for photo exposure.

Example 20

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the polymer 4 was used instead of polymer 1and the spin speed used was 2000 rpm for 30 seconds.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 89.2° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 21

An experiment was performed with similar combination as in Example 10,except that the polymer 1 is replaced by polymer 4 listed in Example 20.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 4 and polymer 2 in ratio of 0.5:99.5 per weight % and the spinspeed used was 2000 rpm for 30 seconds.

A tilt angle of 0.04° was measured using the crystal rotation method.The cell was arranged between crossed polarizers without any voltageapplied, with the director of liquid crystal in the cell set at 45° tothe axis of crossed polarizers, and the cell has bright appearance whichconcludes that the liquid crystal molecules were oriented almost planar.The cell was again arranged between crossed polarizers without anyvoltage applied, with the director of liquid crystal in the cell set at0° to any one of the transmission axis of the polarizers, the cell hasdark appearance, which concludes the well defined azimuthal orientationdirection of liquid crystal lying in the polarization plane of the LPUVlight used for photo exposure.

Example 22

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the polymer 5 was used instead of polymer 1and the spin speed used was 1300 rpm for 30 seconds.

The liquid crystal in the cell showed well defined homeotropicorientation. A tilt angle of 89.9° was measured using the crystalrotation method. Upon applying a voltage of 5V to the electrodes of thecell, the liquid crystal molecules switched from the verticalorientation to a planar orientation, which was observed by arranging thecell between crossed polarizers. The azimuthal orientation direction ofthe switched liquid crystals was determined to lie in the polarizationplane of the LPUV light used for photo-exposure.

Example 23

An experiment was performed with similar combination as in Example 6,except that the polymer 1 is replaced by polymer 5 listed in Example 22.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 5 and polymer 2 in ratio of 4:96 per weight % and the spin speedused was 2000 rpm for 30 seconds.

A tilt angle of 28° was measured using the crystal rotation method. Thecell was arranged between crossed polarizers without any voltageapplied, with the director of liquid crystal in the cell set at 45° tothe axis of crossed polarizers, and the cell has bright appearance whichconcludes that the liquid crystal molecules were oriented planar. Thecell was again arranged between crossed polarizers without any voltageapplied, with the director of liquid crystal in the cell set at 0° toany one of the transmission axis of the polarizers, the cell has darkappearance, which concludes the well defined azimuthal orientationdirection of liquid crystal lying in the polarization plane of the LPUVlight used for photo exposure.

Example 24

An experiment was performed with similar combination as in Example 9,except that the polymer 1 is replaced by polymer 5 listed in Example 22.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 5 and polymer 2 in ratio of 1:99 per weight % and the spin speedused was 2000 rpm for 30 seconds.

A tilt angle of 0.09° was measured using the crystal rotation method.The cell was arranged between crossed polarizers without any voltageapplied, with the director of liquid crystal in the cell set at 45° tothe axis of crossed polarizers, and the cell has bright appearance whichconcludes that the liquid crystal molecules were oriented almost planar.The cell was again arranged between crossed polarizers without anyvoltage applied, with the director of liquid crystal in the cell set at0° to any one of the transmission axis of the polarizers, the cell hasdark appearance, which concludes the well defined azimuthal orientationdirection of liquid crystal lying in the polarization plane of the LPUVlight used for photo exposure.

Example 25

An experiment was performed with similar combination as in Example 5,except that the polymer 1 is replaced by polymer 6.

A cell was prepared with the same processing and exposure conditions asin Example 1, except that the solution used is a blend composition ofpolymer 6 and polymer 2 in ratio of 5:95 per weight % and the spin speedused was 1800 rpm for 30 seconds.

A tilt angle of 0.2° was measured using the crystal rotation method. Thecell was arranged between crossed polarizers without any voltageapplied, with the director of liquid crystal in the cell set at 45° tothe axis of crossed polarizers, and the cell has bright appearance whichconcludes that the liquid crystal molecules were oriented almost planar.The cell was again arranged between crossed polarizers without anyvoltage applied, with the director of liquid crystal in the cell set at0° to any one of the transmission axis of the polarizers, the cell hasdark appearance, which concludes the well defined azimuthal orientationdirection of liquid crystal lying in the polarization plane of the LPUVlight used for photo exposure.

Example 26

From Examples 1 to 25, the anisotropic orientation of liquid crystal incells were observed. Another experiment was performed where theanisotropic orientation of liquid crystal polymer was observed.

Blend composition listed in Example 11 was used for this experiment. Aglass substrate was processed with this above blend composition similarto the processing steps in Example 1, except that only one substrate isused for processing and no liquid crystal is used. This coated substratewas subjected to a second process step by spin coating with liquidcrystal polymer 1 at a spin speed of 1200 rpm for a duration of 60seconds which gives thickness of around 700 nm, then the coatedsubstrate is placed in atmosphere of nitrogen and cross linked with thehelp of UV A light source at energy dose of 240 mJ/cm².

The above substrate was arranged between crossed polarizers, with thedirector of liquid crystal polymer set at 45° to the axis of crossedpolarizers, and the substrate has bright appearance which concludes thatthe liquid crystal polymer molecules were oriented almost planar. Thesubstrate was again arranged between crossed polarizers, with thedirector of liquid crystal polymer set at 0° to any one of thetransmission axis of the polarizers, the substrate has dark appearance,which concludes the well defined azimuthal orientation direction ofliquid crystal polymer lying in the polarization plane of the LPUV lightused for photo exposure.

Example 27

Similar experiment was performed as in Example 25, except that the blendcomposition listed in Example 12 was used.

Similar observations of orientation as in Example 25 was concluded.

Example 28

A blend 1 was prepared that consisted of 95% by weight of a compound(II) as given in the below table, and 5% by weight of a photoreactivecompound (II) as given in the table below. Blend 1 was dissolved to 2%by weight in cyclopentanone and stirred for half an hour at roomtemperature.

Indium tin oxide (ITO) coated glass plates were used as substrates. Bymeans of spin-coating a solution of blend 1 with a solid content of 2weight percent in cyclopentanone an alignment layer with a dry thicknessof approximately 60 nm was prepared with the spin parameters of 2000 rpmduring 60 s. The alignment layer was subsequently thermally treated on ahot-plate for 10 minutes at a temperature of 180° C. After that, thephoto-alignment layer was vertically exposed to linearly polarised UVBlight (wavelengths between 280 and 320 nm). A dose of 150 mJ/cm² wasapplied at an intensity of 3 mW/cm². In a next step, a 25 weight percentsolution in cyclopentanone of the formulation M1 (Example 1) wasspin-coated on top of the functionalized photo-alignment layer with thespin parameters of 800 rpm during 60 s. A dry film thickness ofapproximately 800 nm was achieved this way. A thermal treatment at atemperature of 40° C. on a hot-plate was then carried out for a durationof 10 minutes.

Compounds (II) are prepared in analogy to methods known in the art suchas for example Polymerisation step: Formation of the polyamic acid

(30.26 mmol) of 4,4′-diaminodiphenyl derivative (4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl thioether, 4,4′-diaminodiphenyl ether,4,4′-diaminodiphenyl glutaric ester) was solubilised in 71 mL of1-methyl-2-pyrrolidone (NMP). The mixture was cooled to 0° C. for 10minutes. (29.66 mmol) of 1,2,3,4-cyclobutanetretracarboxilic aciddianhydride were added to the solution. The mixture was stirred at 0° C.for two hours and then at rt for 3 hours. The reaction gave the polyamicacid precursor having a viscosity of 0.4 dL/g.

1. A photoalignment composition comprising a) 0.001 to 20%, by weight,of at least one photoreactive compound (I) that comprises aphotoalignment group and b) 80 to 99.999% by weight, of at least onecompound (II) that does not comprise a photoalignment group, and c)optionally at least one reactive or non reactive additives, and d)optionally at least one solvent.
 2. A process for the preparation ofphotoalignment material, comprising a) applying a composition, whereinsaid composition has the same meaning and preferences as given above;and then b) optionally drying, and then c) irradiating the appliedcomposition (VII), obtained after step a) or step b), with aligninglight to induce the anisotropy.
 3. A photoalignment material obtainableby the process as described in claim
 2. 4. A photoalignment materialcomprising a composition as claimed in claim
 1. 5. A method of using aphotoalignment material, comprising preparing an unpatterned orpatterned optical or electro optical component and system, multilayersystem, or device with a photoalignment material.
 6. Unpatterned orpatterned optical or electro-optical element, system and devicecomprising structured or unstructured photoalignment material as claimedin claim 3 and as prepared by a process comprising a) applying acomposition, wherein said composition has the same meaning andpreferences as given above; and then b) optionally drying, and then c)irradiating the applied composition (VII), obtained after step a) orstep b), with aligning light to induce the anisotropy.
 7. A method ofusing the photoalignment material as claimed in claim 3, comprisingproviding the photoalignment material as an structured or unstructuredphotalignment layer, for aligning organic or inorganic compounds,wherein the photoalignment material is prepared by a process comprisinga) applying a composition, wherein said composition has the same meaningand preferences as given above; and then b) optionally drying, and thenc) irradiating the applied composition (VII), obtained after step a) orstep b), with aligning light to induce the anisotropy.
 8. A method ofusing an unpatterned or patterned optical or electro-optical element asclaimed in claim 6, comprising preparing a display waveguide, a securityor brand protection element, a bar code, an optical grating, a filter, aretarder, a compensation film, a reflectively polarizing film, anabsorptive polarizing film, an anisotropically scattering filmcompensator and retardation film, a twisted retarder film, a liquidcrystal display, a cholesteric liquid crystal film, a guest-host liquidcrystal film, a monomer corrugated film, a smectic liquid crystal film,a polarizer, a piezoelectric cell, a thin film exhibiting non linearoptical properties, a decorative optical element, a brightnessenhancement film, a component for wavelength-band-selectivecompensation, a component for multi-domain compensation, a component ofmultiview liquid crystal displays, an achromatic retarder, apolarization state correction/adjustment film, a component of optical orelectro-optical sensors, a component of brightness enhancement film, acomponent for light-based telecommunication devices, a G/H-polarizerwith an anisotropic absorber, a reflective circular polarizer, areflective linear polarizer, a MC (monomer corrugated film), twistednematic (TN) liquid crystal displays, hybrid aligned nematic (HAN)liquid crystal displays, electrically controlled birefringence (ECB)liquid crystal displays, supertwisted nematic (STN) liquid crystaldisplays, optically compensated birefringence (OCB) liquid crystaldisplays, pi-cell liquid crystal displays, in-plane switching (IPS)liquid crystal displays, fringe field switching (FFS) liquid crystaldisplays, vertically aligned (VA) liquid crystal displays, or multidomain vertically aligned (MVA) liquid crystal displays with theunpatterned or patterned optical or electro-optical element; wherein allof the displays are applied in either transmissive or reflective ortransflective mode.
 9. Unpatterned or patterned optical orelectro-optical element, system and device comprising structured orunstructured photoalignment material as claimed in claim 4 and asprepared by a process comprising a) applying a composition, wherein saidcomposition has the same meaning and preferences as given above; andthen b) optionally drying, and then c) irradiating the appliedcomposition (VII), obtained after step a) or step b), with aligninglight to induce the anisotropy.
 10. A method of using the photoalignmentmaterial as claimed in claim 4, comprising providing the photoalignmentmaterial as an structured or unstructured photalignment layer, foraligning organic or inorganic compounds, wherein the photoalignmentmaterial is prepared by a process comprising a) applying a composition,wherein said composition has the same meaning and preferences as givenabove; and then b) optionally drying, and then c) irradiating theapplied composition (VII), obtained after step a) or step b), withaligning light to induce the anisotropy.